Fouling characteristics of cooling tower water containing corrosion inhibitors

Miscellaneous · Thu Jan 01 00:00:00 EST 1987

OSTI ID:6085366

Santoso, E

Corrosion inhibitors investigated included zinc-chromate and phosphates. In addition, additives including polyacrylate and phosphonate (HEDP and AMP) were used to determine their effectiveness as antifoulants. The tests were conducted in a simulated cooling tower water system. The parameters investigated were: test section surface temperature 130, 145 and 160{degree}F, velocity in test section 3.0, 5.5 and 8.5 ft/sec, pH 6.0 -8.0, and material of the fouling surface (stainless steel, carbon steel, 90/10 copper/nickel, and admiralty brass). The water bulk temperature in all tests was 115{degree}F. The water had a total hardness of 800-1000 ppm as CaCO{sub 3}, total sulfate of 800-1000 ppm as SO{sub 4} and silica of 40-45 ppm as SiO{sub 2}. For each test, a fouling resistance - time curve was obtained. This curve was fitted to the equation Rf = Rf (1-exp(-({theta}-{theta}d)/{theta}c)) to yield the values of {theta}c and Rf{sup *}. Rf is the fouling resistance predicted by the regression equation, Rf{sup *} is the asymptotic fouling resistance, {theta} is time, {theta}d is dead time and {theta}c is the time constant for the asymptotic decay. The values of {theta}c and Rf{sup *} from regression analysis have been correlated with the various parameters by the Heat Transfer Research, Inc., (HTRI) fouling model. For the range of conditions studied, the correlation equations relate the fouling resistance, Rf, to the surface temperature, wall shear stress and water quality. Seventeen different water qualities were investigated to determine the values of 5 parameters, which are specific for each water quality. For each of the seventeen water qualities studied threshold curves for three threshold values of Rf{sup *} have been developed as a function of velocity and surface temperature. These curves are useful to obtain the conditions required to maintain a desired value of Rf{sup *} in a heat exchanger.

• Research Organization: Oregon State Univ., Corvallis, OR (USA)
• OSTI ID: 6085366
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
ANTIFOULANTS
PERFORMANCE TESTING
COOLING TOWERS
WATER CHEMISTRY
CORROSION INHIBITORS
HEAT EXCHANGERS
FOULING
BRASS
CALCIUM CARBONATES
CARBON STEELS
CHROMATES
COPPER BASE ALLOYS
EQUATIONS
FLOW RATE
HEAT TRANSFER
MEDIUM TEMPERATURE
MINERALS
NICKEL ALLOYS
PH VALUE
PHOSPHONATES
POLYACRYLATES
REGRESSION ANALYSIS
SILICA
STAINLESS STEELS
SULFATES
TIME DEPENDENCE
ZINC COMPOUNDS
ZINC PHOSPHATES
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBONATES
CHALCOGENIDES
CHEMISTRY
CHROMIUM COMPOUNDS
COPPER ALLOYS
ENERGY TRANSFER
ESTERS
HIGH ALLOY STEELS
IRON ALLOYS
IRON BASE ALLOYS
MATHEMATICS
MECHANICAL STRUCTURES
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC POLYMERS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
POLYMERS
POLYVINYLS
SILICON COMPOUNDS
SILICON OXIDES
STATISTICS
STEELS
SULFUR COMPOUNDS
TESTING
TOWERS
TRANSITION ELEMENT COMPOUNDS
ZINC ALLOYS
200101* - Fossil-Fueled Power Plants- Cooling & Heat Transfer Equipment & Systems